James Clapper, the Director of National Intelligence, said "No" when asked in March if the federal government was conducting wholesale spying on law abiding Americans.

Today Sen. Ron Wyden, D-Ore., who asked the question during the March hearing, said he wants Clapper to appear before another hearing to give "straight answers."

Wyden, a member of the Senate Intelligence Committee, has been warning at least since last December against wide spread government snooping. He made clear in a statement today that he gave Clapper plenty of warning last March that he would ask him about prying by the National Security Agency.

"So that he would be prepared to answer, I sent the question to Director Clapper's office a day in advance," Wyden said in a statement today. "After the hearing was over my staff and I gave his office a chance to amend his answer. "

At the hearing, Wyden asked Clapper for a yes or no answer to the question "does the NSA collect any type of data at all on millions or hundreds of millions of Americans?"

In response, Clapper said "No, sir." When Wyden pressed again, Clapper clarified that the government doesn't do it "wittingly," at least.

"There are cases where they could inadvertently perhaps collect, but not wittingly," Clapper said at the hearing in response to Wyden's question.

In recent days, compelled by revelations from former security consultant Edward Snowden, the NSA has admitted there is a secret program called PRISM that has collected data on millions of Americans phone calls and emails.

"Now public hearings are needed to address the recent disclosures and the American people have the right to expect straight answers from the intelligence leadership to the questions asked by their representatives," Wyden said today.

The Office of the Director of National Intelligence did not immediately respond to an ABC News request for comment about Wyden's statement.

Clapper, however, told the National Journal on Friday that he was referring to email surveillance when he answered "no" to Wyden's question, although Wyden did not mention email in his question.

"What I said was, the NSA does not voyeuristically pore through U.S. citizens' e-mails. I stand by that," Clapper told National Journal.

Wyden appears to have been suspicious of the NSA's actions long before Snowden's revelations. Just after Christmas last year, to a largely empty chamber, Wyden warned against the government expanding its preference and ability to collect data on U.S. citizens.

As a member of the Intelligence Committee, Wyden was unable to expressly mention the details of a government program to obtain broad warrants from the secretive Foreign Intelligence Surveillance Court that would allow officials to spy on virtually any law abiding citizen.

"It is never okay, never okay for government officials to use a general warrant to invade the privacy of a law-abiding American," Wyden said on Dec. 27, 2012. "It was not okay for constables and customs officials to do it in colonial days, and it is not okay for the National Security Agency to do it today."

Wyden said the Fourth Amendment guarantees the government must seek a warrant to invade a citizens privacy, a right understood from the earliest days of the Republic.

"The problem, of course, is if you let government officials search any house that they want, they're going to search through the houses of a lot of people who haven't broken any laws," Wyden said. "For more than 200 years this fundamental principle has protected Americans' privacy while still allowing our government to enforce the law and protect public safety."